The depletion of the spectrum available for communications is pushing toward the use of ever higher frequencies.
Furthermore, faced with the expansion of the cable network (ADSL, optical fibers), a radiocommunication service will be justified in the future essentially by a need for mobility.
Mobility assumes omnidirectionality of the antenna system. Unfortunately, the size and therefore the energy sensitivity of an omnidirectional antenna decreases with the frequency. Very high frequencies are therefore by nature difficult to make it compatible with mobility, without abandoning omnidirectional antennas in order to use directive antennas, the difficulty then being to be able to aim the latter dynamically and virtually instantaneously. Three solutions can currently be envisaged according to the prior art.
The motorized parabolic antenna is the conventional and well-known solution. One of its disadvantages is its very poor aiming agility. The aiming of the beam, relying on mechanical motorization, is not instantaneous. It is reserved for point-to-point and not very mobile configurations.
The phase-shift electronic scan antenna allows instantaneous aiming, but it is a solution that is technologically difficult and prohibitively costly. In addition, in point-to-multipoint configuration, it requires using a time division multiple (TDMA) access protocol which is not optimal in the matter of latency in the transmission delay or in the matter of power allocation.
The frequency scan antenna FSA allows instantaneous aiming. It is a proven and low-cost technique similar to the prism in optics. The aiming direction depends on the frequency and the frequency therefore makes it possible to control the aiming direction.